The present invention relates to technology for data storage.
Semiconductor memory has become increasingly popular for use in various electronic devices. For example, non-volatile semiconductor memory is used in cellular telephones, digital cameras, personal digital assistants, mobile computing devices, non-mobile computing devices and other devices. Electrical Erasable Programmable Read Only Memory (EEPROM) and flash memory such as NAND memory are among the most popular non-volatile semiconductor memories.
Non-volatile memories formed from reversible resistance-switching elements are also known. For example, U.S. Patent Application Publication 2006/0250836, published Nov. 9, 2006, and titled “Rewriteable Memory Cell Comprising A Diode And A Resistance-Switching Material,” incorporated herein by reference, describes a rewriteable non-volatile memory cell that includes a diode coupled in series with a reversible resistance-switching material such as a metal oxide or metal nitride. These reversible resistance-switching materials are of interest for use in nonvolatile memory arrays. One resistance state may correspond to a data “0,” for example, while the other resistance state corresponds to a data “1. ” Some of these materials may have more than two stable resistance states. Such switching elements are often arranged in multiple layers in so-called 3-D memory devices. Moreover, various types of volatile memory devices are known, such as DRAM. Both rewritable and write-once memories are known.
A memory device can be in the form of a card or other component which can be inserted into or otherwise connected to a host/user device, such as a host cell phone, digital camera or other device. In other cases, the memory device is permanently installed into the host device. Examples of memory devices with removable media formats are marketed under various trade names including COMPACTFLASH, SMARTMEDIA, SECURE DIGITAL, MEMORY STICK, XD-PICTURE CARD. A new generation of memory card formats with small form factors are sold under trade names including RS-MMC, MINISD AND MICROSD, AND INTELLIGENT STICK.
During a write process, a unit of data referred to as a page is written to a specified location in a memory array. For example, the host device can provide to the memory device the data which is to be written, along with an address of the memory array for writing the data. The memory device includes circuitry for writing the data to the specified address. However, when a write operation fails, such as due to a problem with the memory elements or circuitry associated with the specified address, the resulting input/output operations which attempt to resolve the failure may consume excessive bandwidth.
Techniques are needed for efficiently handling write operation failures in a memory device.